Underwater disconnectible connector

ABSTRACT

An electrical connector of the plug and socket type for use in an electrically conductive environment such as under water. The plug is cylindrical in shape and carries a number of axially spaced contactor bands which are exposed at and in flush relation to the cylindrical surface. The socket, which is of greater diameter than the plug, has an equal number of axially spaced annular contacts which protrude inwardly into the socket to engage the contactor bands of the inserted plug. Each connected pair of contacts is isolated and sealed from the other connected contacts and from the surrounding environment by resilient Orings supported in the socket and axially spaced in alternating arrangement with the socket contacts. Insertion of the plug causes the O-rings to be compressed radially between the cylindrical surface of the plug and the internal surface of the socket.

I United States Patent [151 3,641,479

OBrien et al. 1 Feb. 8, 1972 [54] UNDERWATER DISCONNECTIBLE 3,491,326 1/1970 Pfister et al ..339/19 CONNECTOR Primary Examiner-Joseph H. McGlynn [72] Inventors: Donald G. O'Brien, Framingharn; Edward Atmmey Kenway, Jamey & Hildreth R. Walker, South Natick, both of Mass. [73] Assignee: D. G. OBrlen, lnc., Framingham, Mass. [57] ABSTRACT [22] Filed: June 16 1969 An electrical connector of the plug and socket type for use in an electrically conductive environment such as under water. [21] Appl. No.: 833,614 The plug is cylindrical in shape and carries a number of axially spaced contactor bands which are exposed at and in flush relation to the cylindrical surface. The socket, which is of greater e l. ..339/94 K551911125? diameter than the plug, has an equal number of axially Spaced [58] Field Search 339/8 94 182 183 annular contacts which protrude inwardly into the socket to engage the contactor bands of the inserted plug. Each connected pair of contacts is isolated and sealed from the other [56] cmd connected contacts and from the surrounding environment by UNITED STATES PATENTS resilient O-rings supported in the socket and axially spaced in alternating arrangement with the socket contacts. Insertion of COnlan, Jrthe causes the 0,.rings to be compressed between 3823:13 -----3 3 9 l 7-2 the cylindrical surface of the plug and the internal surface of QC th k t 3,234,500 2/1966 Buckland... ....339/182 3,241,095 3/1966 Phillips ..339l94 M 14 Claims, 4 Drawing Figures 9a 5o |4 1s 20 14 1i 9 8 8 r r sex. a \W ----elw,,,,,' k 2 X l \W L 26 L 1 36 4 8' 10 new 1 1 UNDERWATER DISCONNECTIBLE CONNECTOR SUMMARY OF THE INVENTION Our invention is directed to an electrical connector particularly suited for use in an electrically conductive, fluid environment such as sea water.

The underwater effectiveness of our connector makes it quite valuable in the rapidly expanding technology of marine research and oceanography. For example, sonar transducers are frequently secured to the outside of a submersible or underwater vehicle and are connected electrically to circuitry located within the hull. When replacing or repairing the transducer, it often is necessary to drydock the entire vehicle. Out connector enables such a transducer to be replaced by an underwater diver thereby minimizing the expense and delay of drydocking. The diver need only disassemble the connector, remove the transducer, replace it and reassemble the connector.

In accordance with the invention, the connector includes plug fonned from an electrically insulating material such as, for example, a suitable glass ceramic or plastic material including epoxy resins. One or more contactor bands or plugcontacts are embedded in the plug intermediate its ends and are exposed circumferentially at the cylindrical surface of the plug. The exposed portions of each of the plug contacts are spaced longitudinally of the plug and, in the preferred embodiment of my invention, are in flush relation with the plug to define a contiguous and flush cylindrical plug surface. The socket into which the plug is inserted is of greater cross-sectional diameter than that of the plug so that a clearance may exist between the assembled plug and socket. One or more annular socket contacts are disposed within and extend inwardly into the socket; upon inserfion of the plug each socket contact is resiliently urged inwardly to press firmly and continually against the cylindrical surface of the plug. A socket contact is provided for each of the plug contacts; the socket contacts are spaced longitudinally within the socket to correspond to the longitudinal spacing of the plug contacts; thus, when the plug is inserted fully into the socket, each plug contact will be electrically connected with and firmly gripped by its associated socket contact. O-rings are located so as to isolate each socket contact and are supported within the socket to embrace longitudinally each of the socket contacts. The inner diameter of each O-ring is smaller than the cross-sectional diameter of the plug. Thus, when the plug is inserted into the socket, the plug radially compresses the resilient O-rings which then provide a seal effective to isolate each set of mating plug and socket contacts from each other and from the surrounding environment;

As the plug is inserted into the socket the restriction presented by the inner diameter of the O-rings will cause the cylindrical surface of the plug to be wiped free of dirt or water. An additional O-ring may be provided at the socket entrance further to enhance this wiping action.

The prior art suggests that an underwater connector of the plug and socket type be constructed so that the plug is of equal or greater diameter than that of the socket to enable them to be mated with a snug, interference fit. By providing such an interference fit to wipe and seal the contacts, repeated use of the connector may cause the plug and socket surfaces to wear or deform. As the surfaces become worn or deformed, the sealing and wiping characteristics of the connector become less effective. When this occurs in a connector of the type described in the prior art, the complete plug and socket unit must be replaced. In the connector of my invention, should the O-rings become worn or otherwise ineffective in performing their wiping and sealing functions, it is necessary to replace only the worn O-rings and not the entire connector. Accordingly, it is one object of my invention to provide an underwater disconneetable connector of the axial assembly type which may be readily and inexpensively repaired should repair become necessary.

It is a feature of our invention to provide an underwater disconnectable connector having a plug of smaller cross-sectional dimensions than its receptive socket to preclude wear of the plug and socket.

A further object of our invention is to provide a connector that may rapidly be connected or disconnected by means of a relatively'light assembling force without the aid of any special tools.

It may be appreciated further that as the connector is assembled, arcing may occur between a socket contact and an approaching plug contact. Accordingly, it is another object of our invention to provide a connector in which any arcing that may occur will do so in isolation from the surrounding environment and will be contained between the O-rings. In this regard. our connector is useful in an explosive atmosphere where isolating of arcing is imperative.

Other objects and advantages of our invention will beapparent from the following detailed description with reference to the accompanying drawings wherein:

FIG. 1 is a longitudinal sectional view of our connector with the plug fully inserted in the socket;

FIG. 2 is a longitudinal sectional view of a portion of the socket illustrating the construction of the socket contacts and the O-rings;

FIG. 3 is a view similar to that of FIG. 2 with the plug inserted into the socket; and

FIG. 4 is a sectional view of the mated connector as viewed in the plane of the line 4-4 of FIG. 1.

In the following description, for ease of explanation, the direction in which the plug is inserted into the socket (left to right in FIG. 1) will be referred to as forward and the opposite direction (right to left as seen in FIG. 1) will be referred to asrearwar As shown in FIG. 1 our connector includes a plug generally indicated at 10 and a socket generally indicated at 12. The socket 12 has a cylindrical bore 14 which receives axially the forward end of the plug 10 generally indicated at 16. The forward end or tip 16 of the plug 10 is cylindrical and of smaller cross-sectional diameter than that of the socket bore 14 so that when the plug and socket are mated a definite clearance 17 will exist between the cylindrical surface 18 of the plug andthe socket bore 14 (see FIG. 3). For example, in a connector having a plug tip 16 approximately three-eighths of an inch in diameter the circumferential clearance 17 may be as little as 0.001 inch. A pair of contactor bands 20 and 22 are embedded within the end 16 of the plug. These bands are circumferentially exposed about the surface 18 of the plug. The exposed surface of each of the contactor bands 20, 22'is in flush relation with the remainder of the tip 16 of the plug 10 and defines a portion of the contiguous, flush, cylindrical surface 18 of the plug tip 16. The tip 16 itself is formed from a noneonduetive material so that it may effectively insulate the embedded plug contacts 20 and 22 from each other. We have found vacuum-type ceramic materials and moldable epoxy resins to be suitable for this purpose. These materials have desirable electrical insulating properties. The adhesive properties of epoxy resins provide afirm bond to the metallic plug elements to make the plug tip 16 rigid. If ceramic materials are used, they may be cemented or brazed to the metal support.

The tip 16 of the plug 10 is joined securely to a rearwardly extending connector tube 24 that guides the plug cable 26 and contains the elements, described below, which effect electrical connection between the cable 26 and socket contacts 20 and 22 of the plug I0. As shown in FIG. 1, the plug cable 26 is of conventional coaxial construction having an inner conductor 28 and an outer conductor 30. The cable is connected electrically to the forward tip 16 of the plug 10 by a coaxial plug-in connector generally indicated at 32 which is a commercially available item and includes an outer conductive sleeve 34, an intermediate insulating sleeve 36 and an inner conductive sleeve 38. When assembled, the inner conductor 28 of the cable 26 is received by the inner sleeve 38 of the connector 32 and the outer coaxial conductor 30 is wrapped about the rearward end of the outer sleeve 34. A length of tubing 40 is crimped about the assembled cable 6 and connector 32 to secure the two in a firm electrical connection. An insulating bushing 42 may be placed about the connector 32 adjacent the crimped end of the outer coaxial conductor 28 to preclude an uncrimped end of the conductor 26 from becoming short circuited.

The connector 32 is received within a rearwardly extending portion 44 of a contact sleeve 46 which, as shown in FIG. 1, is formed integrally with the plug contact 20 and engages electrically a collar portion 48 of the outer sleeve 34 of the connector 32. This establishes an electrical connection between the outer coaxial conductor 30 and the plug contact 20.

The inner coaxial conductor 28 is electrically connected to the plug contact 22 by a pin 50 which is brazed at its forward end to the plug contact 22. The pin 50 extends rearwardly through the contact sleeve 46 and is received within the inner sleeve 38 of the plug-in connector 32 to establish electrical contact between the inner coaxial conductor 28 and the plug contact 22.

The end piece 52 of the plug tip 16 is cemented or brazed to the metalcontact member 22 if it is made of ceramic material or is molded to the member 22 if it is of epoxy material. Rings of insulating material 54 and 56 (either ceramic or epoxy) are used to separate the contacts 20 and 22 and also to electrically insulate the contact 20 from the external environment. The rings 54 and 56 are attached to the contact sleeve 46 as illustrated. The ring 56 is reduced in diameter at its rear surface, as at 560 to receive the forward end of the connector tube 24.

The socket assembly 12 includes a socket body 70 that is formed from a readily machinable and electrically insulating material such as polycarbonate plastic rod. A pair of expandable socket contact rings 72 and 74 are contained within accommodating grooves 76 and 78 respectively which are fonned at the cylindrical surface of the inner bore 14 of the socket 12. The longitudinal spacing of the grooves 76, 78 and their associated socket contacts 72, 74 corresponds to the iongitudinal spacing of the plug contacts 20, 22 so that when the plug tip 16 is inserted fully into the socket 12 the mating contacts 20 and 72 as well as 22 and 74 will be in proper electrical contact. As illustrated more clearly in FIG. 2, the socket con tact 72 has a plurality of inwardly. projecting, resilient fingers 73. The socket contact 74 is of identical construction (see FIG. 4). The fingers of the contacts 72 and 74 respectively thus define an inner contact diameter smaller than that of the diameter of the plug tip 16 so that when the plug is inserted into the socket 12 it engages and forces the fingers radially apart. Thus when the plug 10 and socket 12 are mated the fingersof the socket contacts 72, 74, by reason of their resilient construction, press inwardly about the contactor bands 20, 22

of the plug to firmly grip the plug and maintain an effective electrical contact. It should also be noted that, when mated,

' the reduced diameter of the plug at 16 provides the aforementioned circumferential clearance.

As shown in FIG. 1, the socket 12 includes a hollow neck 75 which receives the end of coaxial cable 76 having inner and outer conductors 77, 78. A pair of slots 79, 81 are formed in the neck 75 to guide the conductors 77, 78 to terminal screws 83, 85. A pair of conductive strips 87, 89 extend rearwardly from the screws 83, 85 along the exterior of the socket body 70, the strips 87, 89 terminating adjacent the socket contacts 72, 74 respectively. As shown in FIG. 4, an opening 91 is formed in the socket body 70 to expose the conductive strip 87 to its associated socket contact 74 and to enable the strip 87 and contact 74 to be electrically connected as by a wire 93, for example. The opening 91 then is sealed with an epoxy resin or other curable adhesive material 95. The other strip is connected to its contact in substantially the same manner.

It is imperative that when our connector is used in an un' derwater environment each set of contact pairs 20, 72 ad 22, 74 be sealed from each other so that any water which may be trapped within the clearance 17 of the assembled connector will not cause short circuiting or a low-resistance path to occur between the sets of contacts. For this purpose a number of resilient, compressible O-rings 80, 82, 84 are contained within inner grooves 86, 88 and 90 respectively formed about the inner perimeter of the socket bore 14. The O-rings are desirably of larger cross section than those that would be typically used in a conventional sealing application so'as to insure substantial contact along the surface of the plug in the axial direction. That is, the thickness of each sealing O-ring is considerably larger than the depth of the groove in which is is seated and is considerably less than the width of that groove. Thus as the plug 10 is inserted into the socket 12 the O-rings are compressed radially and wipe the plug surface. When the connector is assembled the O-rings press firmly against the cylindrical surface of the plug 16 to effect a seal between each adjacent set of contacts. Thus the contact 20, 72 is sealed between the O-rings 80 and 82 and the contact 22, 74 is isolated between the O-rings 82 and 84, the O-ring 82 serving as a common sealing member between the contact pair. When our connector is assembled under water the presence of residual water within the grooves 76 and 78 and in the clearance between the plug tip 16 and socket bore 14 will not cause short circuiting between the contact sets since the O- ring seal is also electrically insulating.

An additional Oring 92 may be provided at the entrance end of the socket I2 for the purpose of wiping the plug tip 16 and socket contacts 20, 22 free of dirt before the contacts are electrically mated. Additional O-rings may also be provided at the sealing locations if desired to provide greater reliability and a longer leakage path to improve the electrical characteristics of the connector. An opening 94 is provided at the forward end of the socket to enable water to be ejected from the bore when the plug is inserted and to enable water to freely flow back into the bore when the plug is retracted. Our connector requires only a light force to efiect its connection or disconnection.

In some electrical circuits the presence of excess water or other conductive medium about the electrically connected contacts may deleteriously affect the integrity of the circuit. Furthermore, when an electrical connector is completely surrounded by a conductive medium the possibility of current leakage to the ambient environment is present. When our connector is used under these conditions, we prefer to coat the socket bore 14 with a nonconductive, water-insoluble grease.

A number of commercially available silicone based greases.

may be used. The various grooves formed within the socket should be completely filled. This may be accomplished simply by placing some grease within the socket and then reciprocating theplug tip 16 within the bore 14 until all the grooves and clearances are filled. The resilient socket contacts 72, 74 remain effective to press and grip their associated plug contacts 20, 22 and to make electrical contact even .in the presence of the grease.

Our connector also includes means for securely locking the plug 10 and socket 12 together after they have been electrically assembled. To this end the socket body 70 is provided with a threaded exterior portion about the entrance to the socket which is cooperative with a locknut 102 that is supported for rotation about the connector sleeve 24. The connector sleeve 24 has a shoulder which, at full engagement; abuts the entrance end of the socket body 70. The shoulder 104 serves a dual purpose in that it determines the extent to which the plug tip 16 may be inserted into the socket bore 14 and serves as a retaining member to preclude the separation of the lock nut 102 from the connector sleeve 24.

Protuberances 108 may be provided in the locknut 102 to facilitate normal disengagement of the locknut I02 from the connector sleeve 24 after the connector has been assembled.

From the foregoing it will be apparent that we have provided a versatile, reliable fiuidproof connector that may be connected and disconnected repeatedly within an electrically conductive environment without displaying characteristics adverse to the functioning of the electrical circuit in which the connector is used.

pair of connected contacts when smaller than the corresponding dimension of provide the required clearance. Further, although we The foregoing description is intended only to be illustrative of our invention which may be modified by those skilled in the art without departing from its spirit. For example, although the connector has been described as having two pairs of connectable contacts, it is, of course, possible to construct a connector having any number of contacts, with each of the contacts being isolated by one or more O-rings or similar yieldable, resilient sealing members.

it should be noted that, although the illustrative embodiment of the invention is directed to a plug and socket of circular cross-sectional configuration, an oval or other noncircular cylindrical cross section may be used. when such a noncircular connector is used care should be taken to insure that the configuration is such that O-rings will completely isolate each the connector is assembled. .the cross sectional dimensions of the plug must, of course, be the socket to have shown out connector in connection with a' two conductor coaxial cable, it is apparent that it might be used with cables of the noncoaxial type and with multiple conductor cables.

Having described our invention, what we claim is:

l. A fluidproof electrical connector comprising:

A. a tubular plug of electrically insulating material having at least one electrically conductive plug contact thereon, at least a portion of said plug contact being exposed at the tubular surface of said plug,

B. an electrically insulating socket having a tubular bore of substantially similar cross-sectional shape to that of said plug tubular surface, said bore being of greater cross-sectional dimensions than said plug so that when said plug is inserted into said socket, a clearance exists therebetwen;

C. at least one resilient, outwardly yieldable, electrically conductive socket contact disposed within said socket and protruding inwardly into said bore to present a yieldable restriction to insertion of said plug into said bore;

D. said socket contact being positioned within said socket to be in longitudinal alignment with, and thereby in resiliently engaged contact with, said plug contact when said plug is fully inserted into said socket;

E. a pair of inner perimetric grooves recessing said tubular bore of said socket, with one of said grooves being on either side of said socket contact,

F. at least one resilient sealing ring seated in each said socket groove, each sealing ring having an inner opening of smaller dimension than the cross section of said plug tubular surface, whereby when said plug is fully inserted into said socket, said sealing rings effect a sealed isolation of said electrically connected contacts therebetween, and

G. a nonconductive, water-insoluble, greaselike material disposed in portions of said grooves unoccupied by said sealing rings.

2. A fluidproof electrical connector comprising:

A. a tubular plug of electrically insulating material having at least one electrically conductive plug contact thereon, at least a portion of said plug contact being exposed at the tubular surface of said plug;

B. an electrically insulating socket having a tubular bore of substantially similar cross-sectional shape to that of said plug tubular surface, said bore being of greater cross-sectional dimensions than said plug so that a clearance exists therebetween when said plug is inserted into said socket, said socket bore having a circumferential slot in the surface of said tubular bore;

C. at least one resilient, outwardly yieldable, electrically conductive socket contact disposed within said socket slot and protruding inwardly into said bore to present a yieldable restriction to insertion of said plug into said bore;

D. said socket contact being positioned within said socket to be in longitudinal alignment with, and in resiliently engaged electrical contact with, said plug contact when said plug is fully inserted into said socket;

E. at least one resilient sealing ring disposed within said socket bore on each side of said socket contact, each sealing ring having an inner opening of smaller dimension than the cross section of said plug whereby when said plug is fully inserted into said socket, said sealing rings effect a sealed isolation of said electrically connected contacts therebetween, and

F. a nonconductive, water-insoluble, greaselike material contained within those portions of said slot unoccupied by said socket contact and precluding entrapment of a fluid conductor within said slot.

3. A fluidproof electrical connector comprising:

A. a tubular electrical plug having electrical insulating material seating at least one electrically conductive plug contact thereon with at least a portion of said plug contact exposed at the plug outer tubular surface and with said insulating material exposed at the plug outer tubular surface on either side of said plug contact,

B. an electrical socket having a tubular bore of substantially similar cross-sectional shape to that of said plug outer surface, said bore being of greater cross-sectional size than said plug so that a clearance exists therebetween when said plug is mated with said socket,

C. said socket carrying electrical insulating material for supporting a contact thereon,

D. at least one electrical socket contact carried on said socket seated in said bore on said insulating material thereon, said socket contact being positioned on said socket to be in longitudinal alignment with said plug contact when said plug is matingly engaged with said socket, and said socket contact having a resiliently and radially yielding contact surface protruding inwardly into said bore for resiliently engaging, and maintaining electrical contact with, said plug contact when said plug and socket are matingly engaged,

E. said socket bore further having at least first and second seal-carrying means, with one said means on either side of said socket contact, and

F. at least first and second resilient annular sealing means carried on said socket by said same-numbered seating means, each sealing means having an inner opening constrictionally engaging said insulating material exposed at said plug tubular surface on the corresponding side of said plug contact when said plug is matingly engaged with said socket, and said pair of sealing means effecting a fluidtight seal across said clearance between said matingly engaged plug and socket on either side of said engaged contacts, and insulating with said seals the engagement of said contacts from fluids in said clearance outwardly beyond said sealing means from said contacts. 4. A connector as defined in claim 3 wherein said exposed portion of said plug contact is free of outward projection beyond the tubular plug surface that engages at least said one sealing means more proximal to the opening into said bore.

5. A connector as defined in claim 3 further comprising a resilient annular wiping member carried on said socket adjacent the plug-receiving end of the bore therein, said wiping member interferingly engaging the outer tubular surface of said plug for wiping said plug surface upon mating interconnection of said plug and socket.

6. A connector as defined in claim 3 wherein each said sealcarrying means includes a perimetric groove recessing said tubular bore of said socket.

7. A connector as defined in claim 6 wherein A. each said groove has a width along the tubular bore greater than the depth with which it recesses said bore, and

B. each said sealing means is an annular member which has,

when said socket is disengaged from said plug, a normal width along said tubular bore and a normal thickness transverse to that width, both of which are both less than the width of the groove in which the member is seated and greater than the depth of that groove.

8. A connector as definedmlaim 6 further comprising an electrically nonconductive and water insoluble greaselike material disposed in each said groove and filling the portions therein not occupied by said sealing means.

9. A connector as defined in claim 6 in which said socket has a further perimetric groovelike slot recessing the tubular bore thereof and seating said socket contact.

10. In an electrical connector having a tubular plug carrying a pair of first and second electrical plug contacts spaced apart along the tubular surface thereof, and having a receptacle having a tubular bore therein for receiving said plug in mating engagement spaced inwardly therefrom and having a pair of first and second electrical receptacle contacts, each for mating electrical contact with said same-numbered plug contact, the improvement comprising:

A. first, second and third annular sealing means carried on said receptacle within said bore therein with one said sealing means intermediate said receptacle contacts and each other sealing means on an opposite side of said pair of receptacle contact, each said sealing means resiliently compressively engaging said plug and effecting fluid-type seal between said matingly engaged plug and receptacle on either side of said engaged first contacts and on either side of said engaged second contacts, thereby isolating the engagement of each of said same-numbered contacts from fluids in the plug-to-bore space and outwardly beyond said sealing means from each of said matingly engaged first contacts and second contacts.

11. An electrical connector as defined in claim 10 further comprising means forming a venting aperture through said receptacle from the inner-end of said bore for venting fluid to the exterior of said receptacle from within said bore during the engagement of said plug thereinto.

12. In an electrical connector as defined in claim 10, the further improvement wherein:

A. each of said sealing means includes at least one O-ringlike member seated on said receptacle in a circumferential groove recessing the bore thereof.

13. An electrical connector as defined in claim 12 further comprising electrically insulating and water-insoluble greaselike material disposed in said each groove in the spaces therein not occupied by said O-ring means.

14. A fluidproof electrical connector comprising:

A. a tubular electrical plug having electrical insulating material seating at least one electrically conductive plug contact thereon with at least a portion of said plug contact exposed at the plug outer tubular surface,

B. an electrical socket having a tubular bore of substantially similar cross-sectional shape to that of said plug outer surface, said bore being of greater cross-sectional size than said plug'so that a clearance exists therebetween when said plug is mated with said socket,

C. said socket carrying electrical insulating material for supporting a contact thereon,

D. at least one electrical socket contact carried on said socket seated in said bore on said insulating material thereon, said socket contact being positioned on said socket to be in longitudinal alignment with-said plug contact when said plug is matingly engaged with said socket, and said socket contact having a resiliently and radially yielding contact surface protruding inwardly into said bore for resiliently engaging, and maintaining electrical contact with, said plug contact when said plug and socket are matingly engaged,

E. said socket bore further having at least first and second seal-carrying means, with one said means on either side of said contact, and having an aperture leading from the inner end of said bore to outside said socket, and

F. at least first and second resilient annular sealing means carried on said socket by said same-numbered seating means, each sealing means having an inner opening constrictionally engaging said plug tubular surface on the corresponding side of said Jilug contact when said plug is matingly engaged with sar socket, and said pair of sealing means effecting a fluidtight seal across said clearance between said matingly engaged plug and socket on either side of said engaged contacts, and insulating with said seals the engagement of said contacts from fluids in said clearance outwardly beyond said sealing means from said contacts.

* II! l 

1. A fluidproof electrical connector comprising: A. a tubular plug of electrically insulating material having at least one electrically conductive plug contact thereon, at least a portion of said plug contact being exposed at The tubular surface of said plug; B. an electrically insulating socket having a tubular bore of substantially similar cross-sectional shape to that of said plug tubular surface, said bore being of greater crosssectional dimensions than said plug so that when said plug is inserted into said socket, a clearance exists therebetween; C. at least one resilient, outwardly yieldable, electrically conductive socket contact disposed within said socket and protruding inwardly into said bore to present a yieldable restriction to insertion of said plug into said bore; D. said socket contact being positioned within said socket to be in longitudinal alignment with, and thereby in resiliently engaged contact with, said plug contact when said plug is fully inserted into said socket; E. a pair of inner perimetric grooves recessing said tubular bore of said socket, with one of said grooves being on either side of said socket contact, F. at least one resilient sealing ring seated in each said socket groove, each sealing ring having an inner opening of smaller dimension than the cross section of said plug tubular surface, whereby when said plug is fully inserted into said socket, said sealing rings effect a sealed isolation of said electrically connected contacts therebetween, and G. a nonconductive, water-insoluble, greaselike material disposed in portions of said grooves unoccupied by said sealing rings.
 2. A fluidproof electrical connector comprising: A. a tubular plug of electrically insulating material having at least one electrically conductive plug contact thereon, at least a portion of said plug contact being exposed at the tubular surface of said plug; B. an electrically insulating socket having a tubular bore of substantially similar cross-sectional shape to that of said plug tubular surface, said bore being of greater cross-sectional dimensions than said plug so that a clearance exists therebetween when said plug is inserted into said socket, said socket bore having a circumferential slot in the surface of said tubular bore; C. at least one resilient, outwardly yieldable, electrically conductive socket contact disposed within said socket slot and protruding inwardly into said bore to present a yieldable restriction to insertion of said plug into said bore; D. said socket contact being positioned within said socket to be in longitudinal alignment with, and in resiliently engaged electrical contact with, said plug contact when said plug is fully inserted into said socket; E. at least one resilient sealing ring disposed within said socket bore on each side of said socket contact, each sealing ring having an inner opening of smaller dimension than the cross section of said plug whereby when said plug is fully inserted into said socket, said sealing rings effect a sealed isolation of said electrically connected contacts therebetween, and F. a nonconductive, water-insoluble, greaselike material contained within those portions of said slot unoccupied by said socket contact and precluding entrapment of a fluid conductor within said slot.
 3. A fluidproof electrical connector comprising: A. a tubular electrical plug having electrical insulating material seating at least one electrically conductive plug contact thereon with at least a portion of said plug contact exposed at the plug outer tubular surface and with said insulating material exposed at the plug outer tubular surface on either side of said plug contact, B. an electrical socket having a tubular bore of substantially similar cross-sectional shape to that of said plug outer surface, said bore being of greater cross-sectional size than said plug so that a clearance exists therebetween when said plug is mated with said socket, C. said socket carrying electrical insulating material for supporting a contact thereon, D. at least one electrical socket contact carried on said socket seated in said bore on said insulatiNg material thereon, said socket contact being positioned on said socket to be in longitudinal alignment with said plug contact when said plug is matingly engaged with said socket, and said socket contact having a resiliently and radially yielding contact surface protruding inwardly into said bore for resiliently engaging, and maintaining electrical contact with, said plug contact when said plug and socket are matingly engaged, E. said socket bore further having at least first and second seal-carrying means, with one said means on either side of said socket contact, and F. at least first and second resilient annular sealing means carried on said socket by said same-numbered seating means, each sealing means having an inner opening constrictionally engaging said insulating material exposed at said plug tubular surface on the corresponding side of said plug contact when said plug is matingly engaged with said socket, and said pair of sealing means effecting a fluidtight seal across said clearance between said matingly engaged plug and socket on either side of said engaged contacts, and insulating with said seals the engagement of said contacts from fluids in said clearance outwardly beyond said sealing means from said contacts.
 4. A connector as defined in claim 3 wherein said exposed portion of said plug contact is free of outward projection beyond the tubular plug surface that engages at least said one sealing means more proximal to the opening into said bore.
 5. A connector as defined in claim 3 further comprising a resilient annular wiping member carried on said socket adjacent the plug-receiving end of the bore therein, said wiping member interferingly engaging the outer tubular surface of said plug for wiping said plug surface upon mating interconnection of said plug and socket.
 6. A connector as defined in claim 3 wherein each said seal-carrying means includes a perimetric groove recessing said tubular bore of said socket.
 7. A connector as defined in claim 6 wherein A. each said groove has a width along the tubular bore greater than the depth with which it recesses said bore, and B. each said sealing means is an annular member which has, when said socket is disengaged from said plug, a normal width along said tubular bore and a normal thickness transverse to that width, both of which are both less than the width of the groove in which the member is seated and greater than the depth of that groove.
 8. A connector as defined in claim 6 further comprising an electrically nonconductive and water insoluble greaselike material disposed in each said groove and filling the portions therein not occupied by said sealing means.
 9. A connector as defined in claim 6 in which said socket has a further perimetric groovelike slot recessing the tubular bore thereof and seating said socket contact.
 10. In an electrical connector having a tubular plug carrying a pair of first and second electrical plug contacts spaced apart along the tubular surface thereof, and having a receptacle having a tubular bore therein for receiving said plug in mating engagement spaced inwardly therefrom and having a pair of first and second electrical receptacle contacts, each for mating electrical contact with said same-numbered plug contact, the improvement comprising: A. first, second and third annular sealing means carried on said receptacle within said bore therein with one said sealing means intermediate said receptacle contacts and each other sealing means on an opposite side of said pair of receptacle contact, each said sealing means resiliently compressively engaging said plug and effecting a fluid-type seal between said matingly engaged plug and receptacle on either side of said engaged first contacts and on either side of said engaged second contacts, thereby isolating the engagement of each of said same-numbered contacts from fluids in the plug-to-bore space and outwardly beyond said sealing means from each of said matingly engaged first contaCts and second contacts.
 11. An electrical connector as defined in claim 10 further comprising means forming a venting aperture through said receptacle from the inner-end of said bore for venting fluid to the exterior of said receptacle from within said bore during the engagement of said plug thereinto.
 12. In an electrical connector as defined in claim 10, the further improvement wherein: A. each of said sealing means includes at least one O-ring-like member seated on said receptacle in a circumferential groove recessing the bore thereof.
 13. An electrical connector as defined in claim 12 further comprising electrically insulating and water-insoluble greaselike material disposed in said each groove in the spaces therein not occupied by said O-ring means.
 14. A fluidproof electrical connector comprising: A. a tubular electrical plug having electrical insulating material seating at least one electrically conductive plug contact thereon with at least a portion of said plug contact exposed at the plug outer tubular surface, B. an electrical socket having a tubular bore of substantially similar cross-sectional shape to that of said plug outer surface, said bore being of greater cross-sectional size than said plug so that a clearance exists therebetween when said plug is mated with said socket, C. said socket carrying electrical insulating material for supporting a contact thereon, D. at least one electrical socket contact carried on said socket seated in said bore on said insulating material thereon, said socket contact being positioned on said socket to be in longitudinal alignment with said plug contact when said plug is matingly engaged with said socket, and said socket contact having a resiliently and radially yielding contact surface protruding inwardly into said bore for resiliently engaging, and maintaining electrical contact with, said plug contact when said plug and socket are matingly engaged, E. said socket bore further having at least first and second seal-carrying means, with one said means on either side of said contact, and having an aperture leading from the inner end of said bore to outside said socket, and F. at least first and second resilient annular sealing means carried on said socket by said same-numbered seating means, each sealing means having an inner opening constrictionally engaging said plug tubular surface on the corresponding side of said plug contact when said plug is matingly engaged with said socket, and said pair of sealing means effecting a fluidtight seal across said clearance between said matingly engaged plug and socket on either side of said engaged contacts, and insulating with said seals the engagement of said contacts from fluids in said clearance outwardly beyond said sealing means from said contacts. 